Seismic ground-roll noise attenuation using deep learning     

Harpreet Kaur  Sergey Fomel  Nam Pham 《Geophysical Prospecting》2020,68(7):2064-2077

We propose to adopt a deep learning based framework using generative adversarial networks for ground-roll attenuation in land seismic data. Accounting for the non-stationary properties of seismic data and the associated ground-roll noise, we create training labels using local time–frequency transform and regularized non-stationary regression. The basic idea is to train the network using a few shot gathers such that the network can learn the weights associated with noise attenuation for the training shot gathers. We then apply the learned weights to test ground-roll attenuation on shot gathers, that are not a part of training input to obtain the desired signal. This approach gives results similar to local time–frequency transform and regularized non-stationary regression but at a significantly reduced computational cost. The proposed approach automates the ground-roll attenuation process without requiring any manual input in picking the parameters for each shot gather other than in the training data. Tests on field-data examples verify the effectiveness of the proposed approach.  相似文献   

Prediction of Rock Size Distribution in Mine Bench Blasting Using a Novel Ant Colony Optimization-Based Boosted Regression Tree Technique     

Zhang  Shike  Bui  Xuan-Nam  Trung  Nguyen-Thoi  Nguyen  Hoang  Bui  Hoang-Bac 《Natural Resources Research》2020,29(2):867-886

Natural Resources Research - In this paper, we used artificial intelligence (AI) techniques to investigate the relation between the rock size distribution (RSD) and blasting parameters for rock...  相似文献   

Daily precipitation concentration in Central Coast Vietnam     

Benhamrouche  Aziz  Martin-Vide  Javier  Pham  Quoc Bao  Kouachi  Mostefa E.  Moreno-Garcia  M. Carmen 《Theoretical and Applied Climatology》2022,147(1-2):37-45

Theoretical and Applied Climatology - Empirical frequency distribution of daily precipitation amounts can be fitted by a negative exponential distribution, because anywhere there are many small...  相似文献   

Correction to: Hydro-geochemical characteristics of the groundwater resources in the southern part of the Red River’s Delta plain,Vietnam     

Hoan V. Hoang  Lam V. Nguyen  Nhan D. Dang  Frank Wagner  Nhan Q. Pham 《Environmental Earth Sciences》2018,77(20):714

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Electroconducting Elements of the Ultradeep Fluid–Fault Systems as Indicators of Seismically Active Zones of the Eastern Margin of the Eurasian Continent: Evidence from Magnetotelluric Data     

Nikiforov  V. M.  Shkabarnya  G. N.  Kaplun  V. B.  Zhukovin  A. Yu.  Varentsov  I. M.  Palshin  N. A.  Cuong  D. H.  Trung  N. N.  Hung  D. Q. 《Doklady Earth Sciences》2018,480(2):831-838

Doklady Earth Sciences - A fundamentally new conclusion that zones of high seismic activity are controlled by electroconducting (fluid-saturated) fragments rather than by the entire deep fault is...  相似文献   

Flood vulnerability and buildings’ flood exposure assessment in a densely urbanised city: comparative analysis of three scenarios using a neural network approach     

Pham  Quoc Bao  Ali  Sk Ajim  Bielecka  Elzbieta  Calka  Beata  Orych  Agata  Parvin  Farhana  Łupikasza  Ewa 《Natural Hazards》2022,113(2):1043-1081

Natural Hazards - Advances in the availability of multi-sensor, remote sensing-derived datasets, and machine learning algorithms can now provide an unprecedented possibility to predict flood events...  相似文献   

Lang Trang Cave (Northern Vietnam): Pleistocene Mammalian Locality with Gigantopithecus Finds     

Lopatin  A. V.  Golovachev  I. V.  Serdyuk  N. V.  Maschenko  E. N.  Vislobokova  I. A.  Dac  Le Xuan  Phuong  Pham Mai  Parkhaev  P. Yu.  Syromyatnikova  E. V. 《Doklady Earth Sciences》2022,504(2):372-379

Doklady Earth Sciences - Speleological, geological and paleontological characteristics of the Lang Trang cave in northern Vietnam are presented. Primates Gigantopithecus blacki von Koenigswald,...  相似文献   

Flood-prone area mapping using machine learning techniques: a case study of Quang Binh province,Vietnam     

Luu  Chinh  Bui  Quynh Duy  Costache  Romulus  Nguyen  Luan Thanh  Nguyen  Thu Thuy  Van Phong  Tran  Van Le  Hiep  Pham  Binh Thai 《Natural Hazards》2021,108(3):3229-3251

Natural Hazards - Vietnam’s central coastal region is the most vulnerable and always at flood risk, severely affecting people’s livelihoods and socio-economic development. In...  相似文献   

Sustainable groundwater development in the coastal Tra Vinh province in Vietnam under saltwater intrusion and climate change     

Van  Tuc Dang  Zhou  Yangxiao  Stigter  Tibor Y.  Van  Tuan Pham  Hong  Hai Dao  Uyen  Thanh Dong  Tran  Vuong Bui 《Hydrogeology Journal》2023,31(3):731-749

Three-dimensional transient groundwater flow and saltwater transport models were constructed to assess the impacts of groundwater abstraction and climate change on the coastal aquifer of Tra Vinh province (Vietnam). The groundwater flow model was calibrated with groundwater levels (2007–2016) measured in 13 observation wells. The saltwater transport model was compared with the spatial distribution of total dissolved solids. Model performance was evaluated by comparing observed and simulated groundwater levels. The projected rainfalls from two climate models (MIROC5 and CRISO Mk3.6) were subsequently used to simulate possible effects of climate changes. The simulation revealed that groundwater is currently depleted due to overabstraction. Towards the future, groundwater storage will continue to be depleted with the current abstraction regime, further worsening in the north due to saltwater intrusion from inland trapped saltwater and on the coast due to seawater intrusion. Notwithstanding, the impact from climate change may be limited, with the computed groundwater recharge from the two climate models revealing no significant change from 2017 to 2066. Three feasible mitigation scenarios were analyzed: (1) reduced groundwater abstraction by 25, 35 and 50%, (2) increased groundwater recharge by 1.5 and 2 times in the sand dunes through managed aquifer recharge (reduced abstraction will stop groundwater-level decline, while increased recharge will restore depleted storage), and (3) combining 50% abstraction reduction and 1.5 times recharge increase in sand dune areas. The results show that combined interventions of reducing abstraction and increasing recharge are necessary for sustainable groundwater resources development in Tra Vinh province.

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ALMA observations of the circumstellar envelope around EP Aqr     

Pham Thi Tuyet Nhung  Do Thi Hoai  Pham Tuan-Anh  Thibaut Le Bertre  Pierre Darriulat  Pham Ngoc Diep  Nguyen Thi Phuong  Nguyen Thi Thao  Jan Martin Winters 《天文和天体物理学研究(英文版)》2019,(3)

Atacama Large Millimetre/sub-millimetre Array(ALMA) observations of CO(1–0) and CO(2–1) emissions from the circumstellar envelope of the asymptotic giant branch(AGB) star EP Aqr have been made with four times better spatial resolution than previously available. They are analysed with emphasis on the de-projection in space of the effective emissivity and flux of matter using as input a prescribed configuration of the velocity field, assumed to be radial. The data are found to display an intrinsic axisymmetry with respect to an axis making a small angle with respect to the line of sight. A broad range of wind configurations, from prolate(bipolar) to oblate(equatorial) has been studied and found to be accompanied by significant equatorial emission. Qualitatively, the effective emissivity is enhanced near the equator to produce the central narrow component observed in the Doppler velocity spectra and its dependence on star latitude generally follows that of the wind velocity with the exception of an omni-present depression near the poles. In particular, large equatorial expansion velocities produce a flared disc or a ring of effective emissivity and mass loss. The effect on the determination of the orientation of the star axis of radial velocity gradients, and possibly competing rotation and expansion in the equatorial disc, is discussed. In general,the flux of matter is found to reach a broad maximum at distances of the order of 500 AU from the star.Arguments are given that may be used to favour one wind velocity distribution over another. As a result of the improved quality of the data, a deeper understanding of the constraints imposed on morphology and kinematics has been obtained.  相似文献